This invention relates to tote boxes and more particularly to tote boxes made from foldable box blanks and having self locking rails to hold the blanks in an erected, assembled relationship.
Containers which are returnable/reusable are useful for the transportation, storage, and display of goods in commerce. Such containers, commonly called tote boxes, must be of sufficiently rigid construction to enable safe and damage free transport and storage of goods contained therein. These tote boxes are frequently designed so as to be stacked or mounted in a nesting relation for convenient transportation or storage of the tote boxes. In order to be stackable, the upper edge of the tote box is typically reinforced with a top rail or rim member which is adapted to receive another tote box stacked thereupon.
It is conventional to use a variety of materials for the construction of such tote boxes. Such materials typically consist of corrugated paperboard, corrugated plastic sheet, sheet metal and other such materials which are not sufficiently rigid to support a number of filled tote boxes in stacked relation. Therefore, it is also conventional to reinforce the corners of the tote boxes with structural supports so that a lower tote box of a stack of tote boxes can adequately support the load of the upper tote boxes and goods therein without deformation, possibly resulting in damage to the goods contained therein.
Typically these tote box corner supports and top rails require additional fasteners such as rivets, staples, screws or the like to secure the top rail and the corner support to the box itself. These fasteners add material costs and manufacturing steps to the construction of the tote box thereby resulting in an expensive and difficult to assemble tote box.
One patent which discloses a tote box having corner supports or enhancers and a top rail which are not held in place with additional fasteners such as rivets, staples, screws or the like is applicants"" own U.S. Pat. No. 6,305,601. However, in each of the embodiments of the tote box disclosed in this patent, the corner enhancers extend outwardly from the generally planar surfaces of the tote box walls. Occasionally, one of the vertically oriented outer edges of a corner enhancer may catch on an obstacle such as a fork lift. The resultant force may cause at least one of the outer walls of the corner enhancer to deform and at least one of the interior walls of the corner enhancer to fold inward. When this occurs, the walls of the tote box may separate from the corner enhancers, resulting in a loss of integrity of the box structure as well as the ability to support the weight of another container stacked on top of it.
Accordingly, it is a primary objective of the present invention to provide a tote box which may withstand significant forces applied to the corner enhancers of the tote box.
The present invention is directed to a tote box which is assembled from a die cut box blank, corner enhancers, corner strengthener clips and a self-locking top rail. When folded into the appropriate shape, the die cut box blank results in a bottom, two opposed end walls, and two opposed side walls. The end walls and side walls have upper edges defining a top edge of the box. A pair of opposed walls preferably have holes into which reinforcing hand holds may be inserted to aid in manual handling of a loaded tote box.
To hold the erected box blank in an assembled relationship and to reinforce the top edge of the tote box, a channel shaped top rail extends around the top edge of the tote box. At least a portion of this top rail has a downwardly open channel formed between a pair of channel side walls. When the downwardly open channel of the piece is pushed down over the top edge of the erected box blank, the channel fits over a double thickness of the tote box formed from tabs or flaps of the box blank. The top rail is locked onto the top edge of the box as the result of an inwardly extending hook on at least one channel side wall which snaps beneath one or more tabs. The tabs may extend downwardly from the upper edges of the box walls or be integrally formed in the box walls, as disclosed in applicant""s U.S. Pat. No. 6,305,601, which is fully incorporated by reference herein.
The top rail may be manufactured from a single piece of extruded plastic, aluminum or other material such as is disclosed in applicant""s U.S. Pat. No. 6,305,601. However, the top rail may be alternatively constructed of multiple pieces such as the top rail disclosed in applicant""s U.S. Pat. No. 6,349,877, which is fully incorporated by reference herein. The inwardly extending hook of at least one channel side wall of the top rail engages the tabs of the box walls thereby securing the top rail onto the top edge of the tote box without the need for further fasteners such as screws, rivets, or staples. The top rail preferably has a vertical lip which extends upwardly from the top rail. The vertical lip enables nested stacking of additional tote boxes. A first or upper tote box may be nestably stacked on a second or lower tote box by placing the bottom of the first tote box within the vertical lip of the top rail of the second or lower tote box.
Structural corner enhancers reside at each corner of the tote box to hold the erected side and end walls together in an assembled relationship and to stiffen the tote box corners. The corner enhancers provide a load path for the weight of the stacked tote boxes and their contents to be distributed downwardly and thereby provide structural integrity to the tote box and prevent side and end wall deformation. Each corner enhancer has a first and second open leg channel, each open leg channel being formed between a pair of leg channel walls. Each of the open leg channels has a width of approximately the thickness of the box blank. One of the end walls is held inside one of the open leg channels of a corner enhancer and one of the side walls is held inside the other open leg channel of the corner enhancer. In this manner, each corner enhancer functions to join together an end wall and a side wall in an orthogonal or right angle relationship. Upon assembly, each corner enhancer has an upper portion which may be located inside the downwardly open channel of the top rail.
Corner strengthener clips reside at the bottom of each corner enhancer to prevent the side and end walls of the box from becoming dislodged from the corner enhancers. They provide further structural integrity to the tote box and prevent deformation of the leg channel walls of the corner enhancers in the event something catches on one of the corner enhancers. Each corner strengthener clip has a receptacle formed between a pair of inner and outer receptacle walls, end walls and a bottom. The receptacle of the clip is generally L-shaped, having two arms. Each arm of the receptacle has a width of approximately the thickness of an inner leg channel wall of the corner enhancer so that the inner leg channel walls of the corner enhancer are held inside the arms of the receptacle. In this manner, each corner strengthener clip functions to stabilize the leg channel walls of the corner enhancer with which it is engaged.
In order to assemble the tote box of the present invention the die cut box blank is erected. The bottom ends of the corner enhancers are inserted into the receptacles of the corner strengthener clips to create corner enhancer assemblies. The side and end walls of the erected box blank are then inserted into the open leg channels of the corner enhancers. A side edge of each side wall and a corresponding side edge of an adjacent end wall are located inside the open leg channels of each of the corner enhancers in order to hold and maintain the walls in an erect vertical position, orthogonal to each other. Once the box blank has been folded, the corner enhancer assemblies assembled and the walls of the box blank inserted into the open leg channels of the corner enhancers at the corners of the box, the top rail is then placed over the upper edges of the box walls.
One advantage of the present invention is that the tote box can be assembled rapidly without the need for intermediate fastener joining steps and without the need for multiple rivets or fasteners such as have been conventional in prior art tote boxes as, for example, in the tote box disclosed in the assignee""s own U.S. Pat. No. 5,037,027. Another advantage of the present invention is that the stackable tote box may be constructed to withstand loads accidentally placed upon the corner enhancers of the product.